[Gasification] torrefied fuel

[Kevin Chisholm]

Dear Dan

The critical component for dioxin formation is chlorine. No chlorine = 
no dioxins.

If garbage or municipal waste is sorted to remove all sources of 
chlorine, then dioxins cannot form.

Some plastics can be significant sources of chlorine... for example, 
PVC's  Others, such as polyethylene, have no chlorine in them, either 
directly, or as plasticizing compounds.

Some sources of PVC's include pipe, siding, lawn furniture, food wrap, 
Medical Waste, etc.

I think it is very important that this issue be addressed in relation to 
Terra Preta, and Torrified Fuels. If not, these processes are in 
potential danger of being lumped in with Incineration.

Best wishes,

Kevin

Daniel Nicoson wrote:
> Doug,
>
> Is it that easy to form a dioxin?  (I don't pretend to be a combustion
> chemist)
>
> Our community (Erie, PA) is having a big debate about building a tire
> gasification power plant.  The nay-sayers are thumping their chests and
> stating there will be dioxins in the exhaust.  I don't know.  I think the
> plant has other issues that will keep it from ever being a commercial
> success.  With the volume of tires they are proposing to use each day, I
> think their biggest environmental concern will be if their supply pile ever
> catches on fire.  I can't imagine a plant running with less than a full day
> or two of fuel on hand...worst part is they are trying to site on an old
> industrial site that is probably cheap but it has a food plant and many
> homes now built up around it.
>
> Dioxin?
>
> Also, one of these days I may get around to building either a gasifier or a
> simple wood furnace to heat my house and/or make electricity.  I also would
> consider burning my household garbage including plastic in that situation.
> Again, is dioxin a possible product?
>
> Thanks,
>
> Dan Nicoson
>
> -----Original Message-----
> From: gasification-bounces at listserv.repp.org
> [mailto:gasification-bounces at listserv.repp.org]On Behalf Of doug.williams
> Sent: Monday, March 10, 2008 4:18 PM
> To: Discussion of biomass pyrolysis and gasification
> Subject: Re: [Gasification] torrefied fuel
>
> Toby,
>
> You suggest:
>   
>>  There appears to be an opportunity for torrified wood fuel to be made at
>> about anywhere.  This is an additional step that could be integrated in
>> pellet production and >combined with blending plastic waste, may go even
>> higher in energy content.  I would note that the burner had better be high
>> temp. for fuels containing 2-3% plastic.  Anybody want to help me start an
>> LLLP and build a fuel plant? I've got some resources for the project.
>>     
>
> Adding unspecified plastics to a torrifying wood , most certainly creates
> the conditions to produce benzene from the wood, and chlorine from the
> plastic, combining into dioxin.
> Height temperature combustion will then result in a dioxin ash particle, and
> that would have to be collected and disposed of as toxic waste. For the
> moment, there does not seem to be an easy way to get around this chemistry,
> at least on the cheap,which seems to be the driver in most of these
> discussions.
> Hope this helps avoid making mistakes.
> Doug Williams,
> Fluidyne.
>
>
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